Private Method Conflict Between Helpers Causes Incorrect Method Call

[OsvaldoGDelRio]

What Ruby, Rails and RSpec versions are you using?

Ruby version: ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux-gnu]
Rails version: 7.1.3.4
RSpec version: 3.13

• rspec-core 3.13.0
• rspec-expectations 3.13.1
• rspec-mocks 3.13.1
• rspec-rails 6.1.3
• rspec-support 3.13.1

Observed behaviour

If two helpers share the name of a private method, the tests will call the last one in alphabetical order.

Expected behaviour

Each Helper should maintain its own methods.

Can you provide an example reproduction?

1. Create a Helper:

# frozen_string_literal: true

module HelperOneHelper
  def super_def
    private_def
  end

  private

  def private_def 
    "HelperOne"
  end
  
end

2. Create anotherone sharing the name of the private method

# frozen_string_literal: true

module HelperTwoHelper
  def super_def_two
    private_def
  end

  private

  def private_def 
    "HelperTwo"
  end
 
end

3. Create the test for the first Helper

# spec/helpers/helper_one_helper_spec.rb
require 'rails_helper'

RSpec.describe HelperOneHelper, type: :helper do
  describe '#super_def' do
    it 'calls the private method and returns the expected string' do
      expect(helper.super_def).to eq("HelperOne")
    end
  end
end

You should get

Example

clone https://github.com/OsvaldoGDelRio/helper-failure
run rspec

[OsvaldoGDelRio]

As far as I can see here is the origin of this:

/var/lib/gems/3.1.0/gems/rspec-rails-6.1.3/lib/rspec/rails/example/helper_example_group.rb

def helper
  _view.tap do |v|
    v.extend(ApplicationHelper) if defined?(ApplicationHelper)
    v.assign(view_assigns)
  end
end

[pirj]

How would it work in the controller if you include both?

[OsvaldoGDelRio]

How would it work in the controller if you include both?

The same way, it uses the method from the last Helper, in this case Helper two. I guess Rspec is just following the same behavior. Surprisingly, I guess we should give different names for the private methods or encapsulate them into another module.

[JonRowe]

👋 Method conflicts like this will cause this behaviour, its not something specific to RSpec except that we include both the helper module under test and ApplicationHelper, this is by design.

[pirj]

The only case I can think of is when you include helper A in controller X, and helper B in controller Y.
If A & B’s overlap, this will work in controllers, but not in specs.
Or am I talking nonsense?

Is this something worth fixing?

[JonRowe]

If they work in controllers they will work in specs, all we do is essentially:

class ThisTestsHelper
  include ApplicationHelper
  include ModuleUnderTest
end

So these must be in ApplicationHelper and must overlap.